Study On Motion Characteristics And Ultimate Strength Of The Installation Vessel With U-Shaped Stern

Float-over technology as a marine topside installing method developed in recent years,has been widely used.its advantages,including safety,reliability,high efficiency,good economic returns,is unmatched by traditional installing method. Offshore platform installation is an important part in developing offshore oil and gas resources,the performance of installation equipment used in this process is vital important.Based on the background of the development of oil and gas resources in East China Sea,a flota-over installation vessel is proposed,which can be applied in the East China Sea where long-period swell domains.The stern of this installation vessel is design to be U-shaped,which is different from T-shaped conventional installation vessel.This paper introduces the main process,key technology and key equipment of float-over installation technology,summarizes latest research about float-over both at home and abroad,grasps relating research status.This paper take the float-over method as the research object,to upper module of sea floating supporting installation for research object,using MOSES established numerical model based on three dimensional potential flow theory.This paper calculates hydrodynamic parameters in frequency domain,mainly including added mass coefficient and radiation damping coefficient,the first-order and the second-order wave force(moment) transfer functin,and so on.Quasi-static coupling analysis of the multi-point mooring system has been carried out in time domain.The vessel's sensitivity to parameters of swell in mixed waves is studied,including significant wave height,swell peak factor,peak periods,and study the effects of the mixture of waves with different proportions of wind sea and swell on the motion characteristics of the installation vessel.This paper checks the strength of mooring system.This paper also study longitudinal strength of the vessel with the hogging bending moment,and establishes three-dimensional finite element model of cabin,carries out comprehensive analysis of the hull of the ship,ensuring the safety of hull design.